What is the common condition characterized by excessive curvature of the spine?

The condition characterized by excessive curvature of the spine is kyphosis. Kyphosis refers specifically to an exaggerated forward rounding of the back, resulting in a hunchback appearance. This curvature occurs in the thoracic region of the spine and can lead to discomfort, postural changes, and potential complications if severe.

Kyphosis can be caused by various factors, including aging, degeneration of the spine, or conditions such as Scheuermann's disease. It is distinct from lordosis, which is an excessive inward curve of the spine, typically in the lumbar region. Spondylolisthesis involves the displacement of one vertebra over another, while disc herniation refers to the protrusion of the intervertebral disc, which can lead to nerve compression. None of these conditions are defined by excessive curvature. Thus, kyphosis is the accurate term for the described condition.